This study will investigate whether life-style factors such as physical activity and diet can enhance insulin action and metabolic control of glucose and Free Fatty Acid metabolism in older men and women with moderate obesity (BMI 27-32 kg/m2, waist/hip ratio greater than or equal to 0.95 for men and greater than or equal to 0.85 for women) and impaired glucose tolerance (IGT). The following hypotheses will be tested: 1) During a hyperinsulinemic euglycemic clamp with prevailing FFA levels, insulin mediated whole body glucose disposal is enhanced to a greater extent after endurance exercise-training with weight loss compared to exercise-training without weight loss. 2) During a HEC with intralipid infusion, the suppressive effects of elevated FFA levels on insulin mediated whole body glucose disposal is reduced to a greater extent after endurance exercise-training with weight loss compared to exercise -training without weight loss. 3) During a HEC, the magnitude of the difference in glucose disposal observed during prevailing and elevated FFA levels is reduced to a greater extent after endurance exercise-training with weight loss compared to exercise-training without weight loss. 4) During a HEC in the presence of prevailing and elevated FFA levels, and endurance exercise training when combined with weight loss leads to a greater suppression of fat oxidation/turnover than exercise training without weight loss. 5) During a HEC in the presence of prevailing and elevated FFA levels, endurance exercise training when combined with weight loss leads to a greater enhancement of skeletal muscle pyruvate dehydrogenase activity, and decrease the acetyl CoA-CoA ratio and citrate concentration. 6) Improvements in glucose and fat metabolism at rest and during a HEC after exercise training and dietary intervention are related to enhanced skeletal muscle pyruvate dehydrogenase activity, and decrease the acetyl CoA-CoA ratio and citrate concentration. 7) Improvements in glucose and fat metabolism at rest and during a HEC after exercise training and dietary intervention are related to changes in body composition and a reduction in abdominal fat.